Method and apparatus for contents information

ABSTRACT

A signal representative of a key is generated from authenticator-value information and key base information. The authenticator-value information represents a specified authenticator value. The key base information contains identification information which is set to reproduce the specified authenticator value according to a predetermined degeneration function. Contents information is encrypted into encryption-resultant contents information in response to the key signal. The key base information and the encryption-resultant contents information are transmitted or recorded.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a method of transmitting contentsinformation. Also, this invention relates to a method of recordingcontents information. In addition, this invention relates to anapparatus for transmitting contents information. Furthermore, thisinvention relates to an apparatus for recording contents information.Also, this invention relates to a transmission medium. In addition, thisinvention relates to a recording medium. Furthermore, this inventionrelates to a method of decrypting contents information. Also, thisinvention relates to an apparatus for decrypting contents information.

[0003] 2. Description of the Related Art

[0004] Japanese published unexamined patent application 10-269289discloses a system for managing the distribution of digital contents. Inthe system of Japanese application 10-269289, a distributor sideencrypts and compresses digital contents into processing-resultantdigital contents. The distributor side transmits theprocessing-resultant digital contents, an encryption-resultant contentskey, and encryption-resultant accounting information to a communicationopposite party. The distributor side implements a process of receiving acharge on the basis of contents use information transmitted from thecommunication opposite party. Then, the distributor side implements aprocess of dividing the received charge among interested personsincluding a copyright holder of the digital contents. On the other hand,a user side (a digital contents player) decrypts and expands theprocessing-resultant digital contents in response to the contents key,thereby reproducing the original digital contents. The user sidesubjects the accounting information to a reducing process responsive tothe use of the digital contents. The user side transmits the reducedaccounting information and the contents use information to thedistributor side.

[0005] Japanese published unexamined patent application 10-283268discloses a system in which a recording medium storesencryption-resultant main information, and also encryption-resultantinformation representing a key for decrypting the encryption-resultantmain information. Non-encrypted information representing conditions ofdecrypting the encryption-resultant main information is added to theencryption-resultant key information. In more detail, theencryption-resultant key information has non-encrypted controlinformation which contains device information and region information.The control information is designed to prevent the encryption-resultantmain information from being copied onto a magnetic recording medium oran optical disc in a user side for illegal use thereof.

[0006] The system of Japanese application 10-283268 has a problem asfollows. The non-encrypted control information in theencryption-resultant key information can easily be altered by a thirdperson. The alteration of the non-encrypted control information enablesthe third person to illegally copy the encryption-resultant maininformation.

SUMMARY OF THE INVENTION

[0007] It is a first object of this invention to provide an improvedmethod of transmitting contents information.

[0008] It is a second object of this invention to provide an improvedmethod of recording contents information.

[0009] It is a third object of this invention to provide an improvedapparatus for transmitting contents information.

[0010] It is a fourth object of this invention to provide an improvedapparatus for recording contents information.

[0011] It is a fifth object of this invention to provide an improvedtransmission medium.

[0012] It is a sixth object of this invention to provide an improvedrecording medium.

[0013] It is a seventh object of this invention to provide an improvedmethod of decrypting contents information.

[0014] It is an eighth object of this invention to provide an improvedapparatus for decrypting contents information.

[0015] A first aspect of this invention provides a method oftransmitting contents information. The method comprises the steps ofgenerating a signal representative of a key from authenticator-valueinformation and key base information, the authenticator-valueinformation representing a specified authenticator value, the key baseinformation containing identification information which is set toreproduce the specified authenticator value according to a predetermineddegeneration function; encrypting contents information intoencryption-resultant contents information in response to the key signal;and transmitting the key base information and the encryption-resultantcontents information.

[0016] A second aspect of this invention provides a method of recordingcontents information. The method comprises the steps of generating asignal representative of a key from authenticator-value information andkey base information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;encrypting contents information into encryption-resultant contentsinformation in response to the key signal; and recording the key baseinformation and the encryption-resultant contents information.

[0017] A third aspect of this invention provides a method oftransmitting contents information. The method comprises the steps ofgenerating a signal representative of a key from authenticator-valueinformation and key base information, the authenticator-valueinformation representing a specified authenticator value, the key baseinformation containing identification information which is set toreproduce the specified authenticator value according to a predetermineddegeneration function; encrypting at least the identificationinformation in the key base information to convert the key baseinformation into encryption-resultant key base information; encryptingcontents information into encryption-resultant contents information inresponse to the key signal; and transmitting the encryption-resultantkey base information and the encryption-resultant contents information.

[0018] A fourth aspect of this invention provides a method of recordingcontents information. The method comprises the steps of generating asignal representative of a key from authenticator-value information andkey base information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; and recording the encryption-resultant key baseinformation and the encryption-resultant contents information.

[0019] A fifth aspect of this invention provides an apparatus fortransmitting contents information. The apparatus comprises means forgenerating a signal representative of a key from authenticator-valueinformation and key base information, the authenticator-valueinformation representing a specified authenticator value, the key baseinformation containing identification information which is set toreproduce the specified authenticator value according to a predetermineddegeneration function; means for encrypting at least the identificationinformation in the key base information to convert the key baseinformation into encryption-resultant key base information; means forencrypting contents information into encryption-resultant contentsinformation in response to the key signal; and means for transmittingthe encryption-resultant key base information and theencryption-resultant contents information.

[0020] A sixth aspect of this invention provides an apparatus forrecording contents information. The apparatus comprises means forgenerating a signal representative of a key from authenticator-valueinformation and key base information, the authenticator-valueinformation representing a specified authenticator value, the key baseinformation containing identification information which is set toreproduce the specified authenticator value according to a predetermineddegeneration function; means for encrypting at least the identificationinformation in the key base information to convert the key baseinformation into encryption-resultant key base information; means forencrypting contents information into encryption-resultant contentsinformation in response to the key signal; and means for recording theencryption-resultant key base information and the encryption-resultantcontents information.

[0021] A seventh aspect of this invention provides a transmission mediumfor transmitting encryption-resultant key base information andencryption-resultant contents information, wherein theencryption-resultant key base information and the encryption-resultantcontents information are generated by the steps of generating a signalrepresentative of a key from authenticator-value information and keybase information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal.

[0022] An eighth aspect of this invention provides a recording mediumloaded with encryption-resultant key base information andencryption-resultant contents information, wherein theencryption-resultant key base information and the encryption-resultantcontents information are generated by the steps of generating a signalrepresentative of a key from authenticator-value information and keybase information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal.

[0023] A ninth aspect of this invention is based on the third aspectthereof, and provides a method wherein the identification information inthe key base information contains at least one of 1) information about aregion or regions corresponding to one or more countries, one or morezones, or one or more spaces, 2) information about identification of anindividual, 3) information about identification of a group of persons,4) information about a rating, 5) information about identification of anapparatus maker or a device maker, 6) information about identificationof a contents provider, 7) information about time, 8) information aboutcontents authors, 9) information about identification of a reproducingapparatus or a reproducing device, 10) information about identificationof a connection apparatus or a connection device, 11) information aboutidentification of a medium on which contents information is recorded,12) information about identification of contents information, and 13)information about accounting.

[0024] A tenth aspect of this invention provides a method oftransmitting contents information. The method comprises the steps ofgenerating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; encrypting contents information into encryption-resultantcontents information in response to the key signal; and transmitting thekey base information and the encryption-resultant contents information.

[0025] An eleventh aspect of this invention provides a method ofrecording contents information. The method comprises the steps ofgenerating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; encrypting contents information into encryption-resultantcontents information in response to the key signal; and recording thekey base information and the encryption-resultant contents information.

[0026] A twelfth aspect of this invention provides a method oftransmitting contents information. The method comprises the steps ofgenerating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; encrypting at least the identification information in the keybase information to convert the key base information intoencryption-resultant key base information; encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; and transmitting the encryption-resultant key baseinformation and the encryption-resultant contents information.

[0027] A thirteenth aspect of this invention provides a method ofrecording contents information. The method comprises the steps ofgenerating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; encrypting at least the identification information in the keybase information to convert the key base information intoencryption-resultant key base information; encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; and recording the encryption-resultant key baseinformation and the encryption-resultant contents information.

[0028] A fourteenth aspect of this invention provides an apparatus fortransmitting contents information. The apparatus comprises means forgenerating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; means for encrypting at least the identification informationin the key base information to convert the key base information intoencryption-resultant key base information; means for encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; and means for transmitting the encryption-resultantkey base information and the encryption-resultant contents information.

[0029] A fifteenth aspect of this invention provides an apparatus forrecording contents information. The apparatus comprises means forgenerating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; means for encrypting at least the identification informationin the key base information to convert the key base information intoencryption-resultant key base information; means for encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; and means for recording the encryption-resultant keybase information and the encryption-resultant contents information.

[0030] A sixteenth aspect of this invention provides a transmissionmedium for transmitting encryption-resultant key base information andencryption-resultant contents information, wherein theencryption-resultant key base information and the encryption-resultantcontents information are generated by the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal.

[0031] A seventeenth aspect of this invention provides a recordingmedium loaded with encryption-resultant key base information andencryption-resultant contents information, wherein theencryption-resultant key base information and the encryption-resultantcontents information are generated by the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal.

[0032] An eighteenth aspect of this invention is based on the twelfthaspect thereof, and provides a method wherein the identificationinformation in the key base information contains at least one of 1)information about a region or regions corresponding to one or morecountries, one or more zones, or one or more spaces, 2) informationabout identification of an individual, 3) information aboutidentification of a group of persons, 4) information about a rating, 5)information about identification of an apparatus maker or a devicemaker, 6) information about identification of a contents provider, 7)information about time, 8) information about contents authors, 9)information about identification of a reproducing apparatus or areproducing device, 10) information about identification of a connectionapparatus or a connection device, 11) information about identificationof a medium on which contents information is recorded, 12) informationabout identification of contents information, and 13) information aboutaccounting.

[0033] A nineteenth aspect of this invention provides a method ofdecrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from authenticator-value information and keybase information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;and encrypting contents information into encryption-resultant contentsinformation in response to the key signal. The method comprises thesteps of reproducing the authenticator-value information representativeof the specified authenticator value from the identification informationin the key base information according to the predetermined degenerationfunction; reproducing the key signal from the reproducedauthenticator-value information and the key base information; anddecrypting the encryption-resultant contents information into theoriginal contents information in response to the reproduced key signal.

[0034] A twentieth aspect of this invention provides a method ofdecrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from authenticator-value information and keybase information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal. The method comprises the steps of decrypting theencryption-resultant key base information into the original key baseinformation; reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the original key base informationaccording to the predetermined degeneration function; reproducing thekey signal from the reproduced authenticator-value information and theoriginal key base information; and decrypting the encryption-resultantcontents information into the original contents information in responseto the reproduced key signal.

[0035] A twenty-first aspect of this invention provides an apparatus fordecrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from authenticator-value information and keybase information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal. The apparatus comprises means for decrypting theencryption-resultant key base information into the original key baseinformation; means for reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the original key base informationaccording to the predetermined degeneration function; means forreproducing the key signal from the reproduced authenticator-valueinformation and the original key base information; and means fordecrypting the encryption-resultant contents information into theoriginal contents information in response to the reproduced key signal.

[0036] A twenty-second aspect of this invention provides a method ofdecrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;and encrypting contents information into encryption-resultant contentsinformation in response to the key signal. The method comprises thesteps of reproducing the authenticator-value information representativeof the specified authenticator value from the identification informationin the key base information according to the predetermined degenerationfunction; reproducing the key signal from the key base information;deciding whether or not the reproduced authenticator-value informationis correct; decrypting the encryption-resultant contents information inresponse to the reproduced key signal when it is decided that thereproduced authenticator-value information is correct; and altering thereproduced key signal into a wrong key signal and decrypting theencryption-resultant contents information in response to the wrong keysignal when it is decided that the reproduced authenticator-valueinformation is not correct.

[0037] A twenty-third aspect of this invention provides a method ofdecrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal. The method comprises the steps of decrypting theencryption-resultant key base information into the original key baseinformation; reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the original key base informationaccording to the predetermined degeneration function; reproducing thekey signal from the original key base information; deciding whether ornot the reproduced authenticator-value information is correct;decrypting the encryption-resultant contents information in response tothe reproduced key signal when it is decided that the reproducedauthenticator-value information is correct; and altering the reproducedkey signal into a wrong key signal and decrypting theencryption-resultant contents information in response to the wrong keysignal when it is decided that the reproduced authenticator-valueinformation is not correct.

[0038] A twenty-fourth aspect of this invention provides an apparatusfor decrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal. The apparatus comprises means for decrypting theencryption-resultant key base information into the original key baseinformation; means for reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the original key base informationaccording to the predetermined degeneration function; means forreproducing the key signal from the original key base information; meansfor deciding whether or not the reproduced authenticator-valueinformation is correct; means for decrypting the encryption-resultantcontents information in response to the reproduced key signal when it isdecided that the reproduced authenticator-value information is correct;and means for altering the reproduced key signal into a wrong key signaland decrypting the encryption-resultant contents information in responseto the wrong key signal when it is decided that the reproducedauthenticator-value information is not correct.

[0039] A twenty-fifth aspect of this invention provides a method ofdecrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;and encrypting contents information into encryption-resultant contentsinformation in response to the key signal. The method comprises thesteps of reproducing the authenticator-value information representativeof the specified authenticator value from the identification informationin the key base information according to the predetermined degenerationfunction; reproducing the key signal from the key base information;deciding whether or not the reproduced authenticator-value informationis correct; decrypting the encryption-resultant contents information inresponse to the reproduced key signal when it is decided that thereproduced authenticator-value information is correct; and failing todecrypt the encryption-resultant contents information in response to thereproduced key signal when it is decided that the reproducedauthenticator-value information is not correct.

[0040] A twenty-sixth aspect of this invention provides a method ofdecrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal. The method comprises the steps of decrypting theencryption-resultant key base information into the original key baseinformation; reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the original key base informationaccording to the predetermined degeneration function; reproducing thekey signal from the original key base information; deciding whether ornot the reproduced authenticator-value information is correct;decrypting the encryption-resultant contents information in response tothe reproduced key signal when it is decided that the reproducedauthenticator-value information is correct; and failing to decrypt theencryption-resultant contents information in response to the reproducedkey signal when it is decided that the reproduced authenticator-valueinformation is not correct.

[0041] A twenty-seventh aspect of this invention provides an apparatusfor decrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal. The apparatus comprises means for decrypting theencryption-resultant key base information into the original key baseinformation; means for reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the original key base informationaccording to the predetermined degeneration function; means forreproducing the key signal from the original key base information; meansfor deciding whether or not the reproduced authenticator-valueinformation is correct; means for decrypting the encryption-resultantcontents information in response to the reproduced key signal when it isdecided that the reproduced authenticator-value information is correct;and means for failing to decrypt the encryption-resultant contentsinformation in response to the reproduced key signal when it is decidedthat the reproduced authenticator-value information is not correct.

[0042] A twenty-eighth aspect of this invention is based on thenineteenth aspect thereof, and provides a method wherein theidentification information in the key base information contains at leastone of 1) information about a region or regions corresponding to one ormore countries, one or more zones, or one or more spaces, 2) informationabout identification of an individual, 3) information aboutidentification of a group of persons, 4) information about a rating, 5)information about identification of an apparatus maker or a devicemaker, 6) information about identification of a contents provider, 7)information about time, 8) information about contents authors, 9)information about identification of a reproducing apparatus or areproducing device, 10) information about identification of a connectionapparatus or a connection device, 11) information about identificationof a medium on which contents information is recorded, 12) informationabout identification of contents information, and 13) information aboutaccounting.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043]FIG. 1 is a block diagram of a system for contents informationaccording to a first embodiment of this invention.

[0044]FIG. 2 is a diagram of the structure of key base information.

[0045]FIG. 3 is a diagram of a key generator in a primary section of thesystem in FIG. 1.

[0046]FIG. 4 is a diagram of a calculator in a secondary section of thesystem in FIG. 1.

[0047]FIG. 5 is a diagram of a key generator in the secondary section ofthe system in FIG. 1.

[0048]FIG. 6 is a block diagram of a system for contents informationaccording to a second embodiment of this invention.

[0049]FIG. 7 is a block diagram of a system for contents informationaccording to a third embodiment of this invention.

[0050]FIG. 8 is a block diagram of a system for contents informationaccording to a fourth embodiment of this invention.

[0051]FIG. 9 is a block diagram of a system for contents informationaccording to a fifth embodiment of this invention.

[0052]FIG. 10 is a block diagram of a system for contents informationaccording to a sixth embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

[0053]FIG. 1 shows a system for contents information according to afirst embodiment of this invention. The system of FIG. 1 includes aprimary section P, a secondary section Q, and an intermediate section R.The primary section P and the secondary section Q are connected to eachother via the intermediate section R.

[0054] The primary section P includes an information recording apparatusor an information transmitting apparatus. The secondary section Qincludes an information reproducing apparatus or an informationreceiving apparatus. An example of the information reproducing apparatusis an information player. The intermediate section R includes arecording medium or a transmission medium. Examples of the recordingmedium are a magnetic recording medium, an optical recording medium, anda semiconductor memory. Examples of the transmission medium are anoptical fiber cable, electric wires, and a radio transmission line. Thetransmission medium is also referred to as a transmission line.

[0055] The primary section P includes a calculator or a key generator 1,a key generator 2, a signal generator 3, and an encryptor 4. Thecalculator 1 receives information being a base of a contents key. Thekey base information is fed from a suitable device (not shown). Thecalculator 1 generates a signal (information) representative of aprimitive key from the key base information according to a predeterminedone-way hash function. The calculator 1 outputs the primitive-key signal(the primitive-key information) to the key generator 2. The one-way hashfunction means a function “h” designed to meet conditions as follows.When a certain value “x” is given in a domain of definition, it isdifficult to calculate a value “y” which satisfies the relation as“h(x)=h(y)”.

[0056]FIG. 2 shows an example of the structure of the key baseinformation. The key base information in FIG. 2 has 56 bits divided intoa first 16-bit block 21, a second 16-bit block 22, a 4-bit block 23, anda 20-bit block 24 which are sequentially arranged in that order. Thefirst 16-bit block 21 represents identification (ID) information of acontents provider. The second 16-bit block 22 represents ID informationof a contents author. The 4-bit block 23 represents ID information of amaker. The 20-bit block 24 represents information peculiar to thesystem.

[0057] The signal generator 3 in FIG. 1 outputs informationrepresentative of a predetermined or specified authenticator value tothe key generator 2. The signal generator 3 includes, for example, amemory loaded with the authenticator-value information or a CPUprogrammed to generate the authenticator-value information.

[0058] The 16-bit contents provider ID information, the 16-bit contentsauthor ID information, and the 4-bit maker ID information in the keybase information are set so that the predetermined authenticator value(the specified authenticator value) can be generated or reproduced bythe secondary section Q according to a predetermined degenerationfunction. Specifically, the secondary section Q uses the 16-bit contentsprovider ID information, the 16-bit contents author ID information, andthe 4-bit maker ID information in the transmitted and received key baseinformation as parameters of the predetermined degeneration function forrecovering the predetermined authenticator value. Correct values of the16-bit contents provider ID information, the 16-bit contents author IDinformation, and the 4-bit maker ID information are open only to alegitimate user. The correct contents provider ID information, thecorrect contents author ID information, and the correct maker IDinformation are referred to as authorized or permitted ID information.

[0059] The key generator 2 produces a signal (information)representative of the contents key in response to the primitive-keyinformation and the authenticator-value information according to apredetermined function. The key generator 2 outputs the contents-keysignal (the contents-key information) to the encryptor 4.

[0060]FIG. 3 shows an example of the key generator 2. The key generator2 in FIG. 3 executes Exclusive-OR operation between the primitive-keyinformation and the authenticator-value information. The key generator 2outputs a signal representative of the result of Exclusive-OR operationas the contents-key information. In this case, Exclusive-OR operationcorresponds to the predetermined function used by the key generator 2.

[0061] The encryptor 4 receives contents information from a suitabledevice (not shown). The device 4 encrypts the contents information intoencryption-resultant contents information in response to thecontents-key signal. The encryptor 4 outputs the encryption-resultantcontents information to the intermediate section R.

[0062] Specifically, the primary section P records theencryption-resultant contents information on the recording medium of theintermediate section R, or transmits the encryption-resultant contentsinformation to the transmission line of the intermediate section R.

[0063] The encryptor 4 may additionally include a compressor. In thiscase, the compressor compresses the contents information, and then theencryptor 4 encrypts the compression-resultant contents information. Thecompression of the contents information is executed in a predeterminedcompressing method such as an MPEG (Moving Picture Experts Group)compressing method. It should be noted that compression-resultantcontents information may be fed to the encryptor 4 from an externaldevice (not shown). In this case, the compressor is omitted from theencryptor 4.

[0064] The encryption by the encryptor 4 may be based on a knownencryption algorithm such as DES (Data Encryption Standard). Accordingto DES, the contents information is encrypted and decrypted 64 bits by64 bits in response to the contents-key signal. In this case, thecontents-key signal corresponds to a 56-bit signal representing a commonkey. The encryption by the encryptor 4 includes a step of dividing every64-bit block of the contents information (or the compression-resultantcontents information) into a pair of 32-bit sub blocks. The encryptionincludes additional steps for signal processing on a sub-block bysub-block basis. The additional steps contain a step of transposingdata, a step of executing permutation of data, a step of processing dataaccording to a nonlinear function, and a step of executing Exclusive-ORoperation between data.

[0065] The primary section P outputs the key base information to theintermediate section R. Specifically, the primary section P records thekey base information on the recording medium of the intermediate sectionR, or transmits the key base information to the transmission line of theintermediate section R.

[0066] The primary section P may further include a second encryptor. Inthis case, the second encryptor encrypts at least part of the key baseinformation to generate encryption-resultant key base information. Forexample, the second encryptor encrypts at least the 16-bit contentsprovider ID information, the 16-bit contents author ID information, andthe 4-bit maker ID information in the key base information. The secondencryptor outputs the encryption-resultant key base information to theintermediate section R. Specifically, in this case, the primary sectionP records the encryption-resultant key base information on the recordingmedium of the intermediate section R, or transmits theencryption-resultant key base information to the transmission line ofthe intermediate section R.

[0067] The encryption-resultant contents information and the key baseinformation (or the encryption-resultant key base information) aretransmitted from the primary section P to the secondary section Qthrough the intermediate section R.

[0068] The secondary section Q includes a calculator or a key generator5, a calculator 6, a key generator 7, and a decrypting device 8. Thecalculator 5 is similar in design and operation to the calculator 1 ofthe primary section P. The calculator 5 receives the key baseinformation from the intermediate section R. The calculator 5 generatesa signal (information) representative of a primitive key from the keybase information according to a predetermined one-way hash functionequivalent to that used by the calculator 1 in the primary section P.The calculator 5 outputs the primitive-key signal (the primitive-keyinformation) to the key generator 7.

[0069] The calculator 6 receives the key base information from theintermediate section R. The calculator 6 generates informationrepresentative of a predetermined or specified authenticator value fromthe 16-bit contents provider ID information, the 16-bit contents authorID information, and the 4-bit maker ID information in the key baseinformation according to a predetermined degeneration function. Theauthenticator value generated by the calculator 6 is equal to that usedin the primary section P. Thus, the calculator 6 reproduces theauthenticator value used in the primary section P. Preferably, thedegeneration function used by the calculator 6 differs from the one-wayhash function used by the calculator 5. The degeneration function usedby the calculator 6 may be the same as the one-way hash function used bythe calculator 5. Correct information of the degeneration function usedby the calculator 6 is open only to a legitimate user. The calculator 6outputs the authenticator-value information to the key generator 7.

[0070]FIG. 4 shows an example of the calculator 6. The calculator 6 inFIG. 4 extracts the 16-bit contents provider ID information, the 16-bitcontents author ID information, and the 4-bit maker ID information fromthe key base information. The calculator 6 executes Exclusive-ORoperation among the 16-bit contents provider ID information, the 16-bitcontents author ID information, and the 4-bit maker ID information. Thecalculator 6 outputs information representative of the result ofExclusive-OR operation as the authenticator-value information. Theauthenticator-value information is also referred to as the degenerationinformation. In this case, Exclusive-OR operation corresponds to thedegeneration function, and the 16-bit contents provider ID information,the 16-bit contents author ID information, and the 4-bit maker IDinformation are used as parameters of the degeneration function.

[0071] The second section Q may further include a second decryptingdevice. In this case, the second decrypting device receives theencryption-resultant key base information from the intermediate sectionR. The second decrypting device decrypts the encryption-resultant keybase information into the original key base information. The seconddecrypting device outputs the original key base information to thecalculators 5 and 6.

[0072] The key generator 7 is similar in design and operation to the keygenerator 2 of the primary section P. The key generator 7 produces asignal (information) representative of a contents key in response to theprimitive-key information and the authenticator-value information (thedegeneration information) according to a predetermined functionequivalent to that used by the key generator 2 in the primary section P.Thus, the key generator 7 reproduces the contents-key signal used in theprimary section P. The key generator 7 outputs the contents-key signal(the contents-key information) to the decrypting device 8.

[0073]FIG. 5 shows an example of the key generator 7. The key generator7 in FIG. 5 executes Exclusive-OR operation between the primitive-keyinformation and the authenticator-value information (the degenerationinformation). The key generator 7 outputs a signal representative of theresult of Exclusive-OR operation as the contents-key information. Inthis case, Exclusive-OR operation corresponds to the predeterminedfunction used by the key generator 7.

[0074] The decrypting device 8 receives the encryption-resultantcontents information from the intermediate section R. Operation of thedecrypting device 8 is inverse with respect to that of the encryptor 4in the primary section P. The decrypting device 8 decrypts theencryption-resultant contents information into the original contentsinformation in response to the contents-key signal. Thus, the decryptingdevice 8 reproduces the original contents information. The decryptingdevice 8 outputs the reproduced contents information.

[0075] In the system of FIG. 1, the 16-bit contents provider IDinformation, the 16-bit contents author ID information, and the 4-bitmaker ID information in the key base information are set so that thepredetermined authenticator value (the specified authenticator value)can be generated according to the predetermined degeneration function.The generated authenticator value is used to reproduce the contents keyfor decrypting the encryption-resultant contents information. Correctvalues of the 16-bit contents provider ID information, the 16-bitcontents author ID information, and the 4-bit maker ID information areopen only to a legitimate user. It is difficult to generate thepredetermined authenticator value by using wrong values of the 16-bitcontents provider ID information, the 16-bit contents author IDinformation, and the 4-bit maker ID information. Therefore, it isdifficult to decrypt the encryption-resultant contents information byusing wrong values of the 16-bit contents provider ID information, the16-bit contents author ID information, and the 4-bit maker IDinformation. Correct information of the predetermined degenerationfunction is open only to a legitimate user. It is difficult to generatethe predetermined authentication value by using wrong information of thepredetermined degeneration function. Therefore, it is difficult todecrypt the encryption-resultant contents information by using wronginformation of the predetermined degeneration function. As understoodfrom the above description, the encryption-resultant contentsinformation is decrypted only when correct values of the 16-bit contentsprovider ID information, the 16-bit contents author ID information, andthe 4-bit maker ID information, and also correct information of thepredetermined degeneration function are available. Accordingly, thecontents information can be surely prevented from being illegallyreproduced or copied.

[0076] The 16-bit contents provider ID information, the 16-bit contentsauthor ID information, and the 4-bit maker ID information in the keybase information may be replaced by at least one of 1) information abouta region or regions corresponding to one or more countries, one or morezones, or one or more spaces, 2) information about identification of anindividual, 3) information about identification of a group of persons,4) information about a rating, 5) information about identification of anapparatus maker or a device maker, 6) information about identificationof a contents provider, 7) information about time, 8) information aboutcontents authors, 9) information about identification of a reproducingapparatus or a reproducing device, 10) information about identificationof a connection apparatus or a connection device, 11) information aboutidentification of a medium on which contents information is recorded,12) information about identification of contents information, and 13)information about accounting.

Second Embodiment

[0077]FIG. 6 shows a system for contents information according to asecond embodiment of this invention. The system of FIG. 6 is similar tothe system of FIG. 1 except for design changes mentioned hereinafter.The system of FIG. 6 includes a primary section PA and a secondarysection QA instead of the primary section P and the secondary section Q(see FIG. 1) respectively.

[0078] The primary section PA is similar to the primary section P exceptthat the key generator 2 and the signal generator 3 (see FIG. 1) areomitted therefrom. In the primary section PA, the calculator (the keygenerator) 1 and the encryptor 4 are directly connected to each other.

[0079] The secondary section QA is similar to the secondary section Qexcept that a key processor 11 replaces the key generator 7 (see FIG.1).

[0080] In the primary section PA, the calculator 1 generates a signal(information) representative of a primitive key from the key baseinformation according to a predetermined one-way hash function. Thecalculator 1 outputs the primitive-key signal (the primitive-keyinformation) to the encryptor 4.

[0081] As shown in FIG. 2, an example of the key base information hasthe 16-bit contents provider ID information, the 16-bit contents authorID information, the 4-bit maker ID information, and the 20-bitsystem-peculiar information.

[0082] The 16-bit contents provider ID information, the 16-bit contentsauthor ID information, and the 4-bit maker ID information in the keybase information are set so that a predetermined or specifiedauthenticator value can be generated by the secondary section QAaccording to a predetermined degeneration function. Specifically, thesecondary section QA uses the 16-bit contents provider ID information,the 16-bit contents author ID information, and the 4-bit maker IDinformation in the transmitted and received key base information asparameters of the predetermined degeneration function for recovering thepredetermined authenticator value. Correct values of the 16-bit contentsprovider ID information, the 16-bit contents author ID information, andthe 4-bit maker ID information are open only to a legitimate user.

[0083] The encryptor 4 receives contents information from a suitabledevice (not shown). The encryptor 4 uses the primitive-key signal as asignal (information) representative of a contents key. The device 4encrypts the contents information into encryption-resultant contentsinformation in response to the contents-key signal. The encryption bythe encryptor 4 may be based on a known encryption algorithm such asDES. The encryptor 4 outputs the encryption-resultant contentsinformation to the intermediate section R.

[0084] Specifically, the primary section PA records theencryption-resultant contents information on the recording medium of theintermediate section R, or transmits the encryption-resultant contentsinformation to the transmission line of the intermediate section R.

[0085] The primary section PA outputs the key base information to theintermediate section R. Specifically, the primary section PA records thekey base information on the recording medium of the intermediate sectionR, or transmits the key base information to the transmission line of theintermediate section R.

[0086] The primary section PA may further include a second encryptor. Inthis case, the second encryptor encrypts at least part of the key baseinformation to generate encryption-resultant key base information. Forexample, the second encryptor encrypts at least the 16-bit contentsprovider ID information, the 16-bit contents author ID information, andthe 4-bit maker ID information in the key base information. The secondencryptor outputs the encryption-resultant key base information to theintermediate section R. Specifically, in this case, the primary sectionPA records the encryption-resultant key base information on therecording medium of the intermediate section R, or transmits theencryption-resultant key base information to the transmission line ofthe intermediate section R.

[0087] The encryption-resultant contents information and the key baseinformation (or the encryption-resultant key base information) aretransmitted from the primary section PA to the secondary section QAthrough the intermediate section R.

[0088] In the secondary section QA, the key processor 11 receives theprimitive-key signal (the primitive-key information) from the calculator5. In addition, the key processor 11 receives the authenticator-valueinformation from the calculator 6. The key processor 11 decides whetheror not the authenticator value represented by the information from thecalculator 6 is correct. When the authenticator value is correct, thekey processor 11 passes the primitive-key signal to the decryptingdevice 8 as it is. When the authenticator value is not correct, the keyprocessor 11 alters or processes the primitive-key signal into a wrongprimitive-key signal and outputs the wrong primitive-key signal to thedecrypting device 8.

[0089] For example, the key processor 11 includes a memory, acomparator, and a signal converter. The memory stores datarepresentative of a correct authenticator value. The memory informs thecomparator of the correct authenticator value. The comparator receivesthe authenticator-value information from the calculator 6. Thecomparator decides whether the authenticator value represented by theinformation from the calculator 6 is equal to or different from thecorrect authenticator value. The comparator informs the signal converterof the result of the decision. The signal converter receives theprimitive-key information from the calculator 5. The signal converter isfollowed by the decrypting device 8. When the result of the decisionindicates that the authenticator value represented by the informationfrom the calculator 6 is equal to the correct authenticator value, thesignal converter falls into a through state. Thus, in this case, thesignal converter passes the primitive-key information to the decryptingdevice 8 as it is. When the result of the decision indicates that theauthenticator value represented by the information from the calculator 6is different from the correct authenticator value, the signal converterfalls into an active state. Thus, in this case, the signal converteralters or processes the primitive-key information into the wrongprimitive-key signal and outputs the wrong primitive-key signal to thedecrypting device 8.

[0090] The decrypting device 8 receives the encryption-resultantcontents information from the intermediate section R. The decryptingdevice 8 uses the primitive-key signal as a signal (information)representative of a contents key. Operation of the decrypting device 8is inverse with respect to that of the encryptor 4 in the primarysection PA. The decrypting device 8 decrypts the encryption-resultantcontents information into the original contents information in responseto the contents-key signal. Thus, the decrypting device 8 reproduces theoriginal contents information. The decrypting device 8 outputs thereproduced contents information.

[0091] In the system of FIG. 6, the correct contents-key signal can befed to the decrypting device 8 only when the reproducedauthenticator-value information is correct. The correct contents-keysignal enables the decrypting device 8 to accurately reproduce theoriginal contents information. On the other hand, a wrong contents-keysignal is fed to the decrypting device 8 when the reproducedauthentication-value information is wrong. The wrong contents-key signalmakes it difficult for the decrypting device 8 to accurately reproducethe original contents information. Accordingly, the contents informationcan be surely prevented from being illegally reproduced or copied.

[0092] The 16-bit contents provider ID information, the 16-bit contentsauthor ID information, and the 4-bit maker ID information in the keybase information may be replaced by at least one of 1) information abouta region or regions corresponding to one or more countries, one or morezones, or one or more spaces, 2) information about identification of anindividual, 3) information about identification of a group of persons,4) information about a rating, 5) information about identification of anapparatus maker or a device maker, 6) information about identificationof a contents provider, 7) information about time, 8) information aboutcontents authors, 9) information about identification of a reproducingapparatus or a reproducing device, 10) information about identificationof a connection apparatus or a connection device, 11) information aboutidentification of a medium on which contents information is recorded,12) information about identification of contents information, and 13)information about accounting.

Third Embodiment

[0093]FIG. 7 shows a system for contents information according to athird embodiment of this invention. The system of FIG. 7 is similar tothe system of FIG. 6 except for design changes mentioned hereinafter.The system of FIG. 7 includes a secondary section QB instead of thesecondary section QA (see FIG. 6).

[0094] The secondary section QB includes a decrypting device 8 a insteadof the decrypting device 8 (see FIG. 6). The decrypting device 8 a isdirectly connected to the calculator 5. The secondary section QBincludes a deciding device 12 connected between the calculator 6 and thedecrypting device 8 a.

[0095] The deciding device 12 receives the authenticator-valueinformation from the calculator 6. The deciding device 12 decideswhether or not the authenticator-value information is correct, that is,whether or not the authenticator value represented by the informationfrom the calculator 6 is correct. The deciding device 12 informs thedecrypting device 8 a of the result of the decision.

[0096] For example, the deciding device 12 includes a memory and acomparator. The memory stores data representative of a correctauthenticator value. The memory informs the comparator of the correctauthenticator value. The comparator receives the authenticator-valueinformation from the calculator 6. The comparator decides whether theauthenticator value represented by the information from the calculator 6is equal to or different from the correct authenticator value. Thecomparator is connected to the decrypting device 8 a. The comparatorinforms the decrypting device 8 a of the result of the decision.

[0097] The decrypting device 8 a receives the primitive-key signal fromthe calculator 5 as a signal (information) representative of a contentskey. The decrypting device 8 a receives the encryption-resultantcontents information from the intermediate section R. The decryptingdevice 8 a is selectively enabled and disabled in response to thedecision result fed from the deciding device 12. When the decisionresult indicates that the authenticator-value information is correct,the decrypting device 8 a is enabled. Thus, in this case, the decryptingdevice 8 a decrypts the encryption-resultant contents information intothe original contents information in response to the contents-keysignal. In other words, the decrypting device 8 a reproduces theoriginal contents information. The decrypting device 8 a outputs thereproduced contents information. When the decision result indicates thatthe authenticator-value information is not correct, the decryptingdevice 8 a is disabled. Thus, in this case, the decrypting device 8 afails to decrypt the encryption-resultant contents information.Accordingly, the contents information can be surely prevented from beingillegally reproduced or copied.

Fourth Embodiment

[0098]FIG. 8 shows a system for contents information according to afourth embodiment of this invention. The system of FIG. 8 is similar tothe system of FIG. 1 except for design changes mentioned hereinafter.The system of FIG. 8 includes a primary section PC and a secondarysection QC instead of the primary section P and the secondary section Q(see FIG. 1) respectively.

[0099] The primary section PC is similar to the primary section P (seeFIG. 1) except that an encryptor 20C is additionally provided. Theencryptor 20C receives the key base information. The device 20C encryptsat least part of the key base information to generateencryption-resultant key base information. For example, the device 20Cencrypts at least the 16-bit contents provider ID information, the16-bit contents author ID information, and the 4-bit maker IDinformation in the key base information. The encryptor 20C outputs theencryption-resultant key base information to the intermediate section R.Specifically, in this case, the primary section PC records theencryption-resultant key base information on the recording medium of theintermediate section R, or transmits the encryption-resultant key baseinformation to the transmission line of the intermediate section R.

[0100] The encryption-resultant contents information and theencryption-resultant key base information are transmitted from theprimary section PC to the secondary section QC through the intermediatesection R.

[0101] The secondary section QC is similar to the secondary section Q(see FIG. 1) except that a decrypting device 22C is additionallyprovided. The decrypting device 22C receives the encryption-resultantkey base information from the intermediate section R. The decryptingdevice 22C decrypts the encryption-resultant key base information intothe original key base information. The decrypting device 22C outputs theoriginal key base information to the calculators 5 and 6.

Fifth Embodiment

[0102]FIG. 9 shows a system for contents information according to afifth embodiment of this invention. The system of FIG. 9 is similar tothe system of FIG. 6 except for design changes mentioned hereinafter.The system of FIG. 9 includes a primary section PD and a secondarysection QD instead of the primary section PA and the secondary sectionQA (see FIG. 6) respectively.

[0103] The primary section PD is similar to the primary section PA (seeFIG. 6) except that an encryptor 20C is additionally provided. Theencryptor 20C receives the key base information. The device 20C encryptsat least part of the key base information to generateencryption-resultant key base information. For example, the device 20Cencrypts at least the 16-bit contents provider ID information, the16-bit contents author ID information, and the 4-bit maker IDinformation in the key base information. The encryptor 20C outputs theencryption-resultant key base information to the intermediate section R.Specifically, in this case, the primary section PD records theencryption-resultant key base information on the recording medium of theintermediate section R, or transmits the encryption-resultant key baseinformation to the transmission line of the intermediate section R.

[0104] The encryption-resultant contents information and theencryption-resultant key base information are transmitted from theprimary section PD to the secondary section QD through the intermediatesection R.

[0105] The secondary section QD is similar to the secondary section QA(see FIG. 6) except that a decrypting device 22C is additionallyprovided. The decrypting device 22C receives the encryption-resultantkey base information from the intermediate section R. The decryptingdevice 22C decrypts the encryption-resultant key base information intothe original key base information. The decrypting device 22C outputs theoriginal key base information to the calculators 5 and 6.

Sixth Embodiment

[0106]FIG. 10 shows a system for contents information according to asixth embodiment of this invention. The system of FIG. 10 is similar tothe system of FIG. 7 except for design changes mentioned hereinafter.The system of FIG. 10 includes a primary section PE and a secondarysection QE instead of the primary section PA and the secondary sectionQB (see FIG. 7) respectively.

[0107] The primary section PE is similar to the primary section PA (seeFIG. 7) except that an encryptor 20C is additionally provided. Theencryptor 20C receives the key base information. The device 20C encryptsat least part of the key base information to generateencryption-resultant key base information. For example, the device 20Cencrypts at least the 16-bit contents provider ID information, the16-bit contents author ID information, and the 4-bit maker IDinformation in the key base information. The encryptor 20C outputs theencryption-resultant key base information to the intermediate section R.Specifically, in this case, the primary section PE records theencryption-resultant key base information on the recording medium of theintermediate section R, or transmits the encryption-resultant key baseinformation to the transmission line of the intermediate section R.

[0108] The encryption-resultant contents information and theencryption-resultant key base information are transmitted from theprimary section PE to the secondary section QE through the intermediatesection R.

[0109] The secondary section QE is similar to the secondary section QB(see FIG. 7) except that a decrypting device 22C is additionallyprovided. The decrypting device 22C receives the encryption-resultantkey base information from the intermediate section R. The decryptingdevice 22C decrypts the encryption-resultant key base information intothe original key base information. The decrypting device 22C outputs theoriginal key base information to the calculators 5 and 6.

What is claimed is:
 1. A method of transmitting contents information,comprising the steps of: generating a signal representative of a keyfrom authenticator-value information and key base information, theauthenticator-value information representing a specified authenticatorvalue, the key base information containing identification informationwhich is set to reproduce the specified authenticator value according toa predetermined degeneration function; encrypting contents informationinto encryption-resultant contents information in response to the keysignal; and transmitting the key base information and theencryption-resultant contents information.
 2. A method of recordingcontents information, comprising the steps of: generating a signalrepresentative of a key from authenticator-value information and keybase information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;encrypting contents information into encryption-resultant contentsinformation in response to the key signal; and recording the key baseinformation and the encryption-resultant contents information.
 3. Amethod of transmitting contents information, comprising the steps of:generating a signal representative of a key from authenticator-valueinformation and key base information, the authenticator-valueinformation representing a specified authenticator value, the key baseinformation containing identification information which is set toreproduce the specified authenticator value according to a predetermineddegeneration function; encrypting at least the identificationinformation in the key base information to convert the key baseinformation into encryption-resultant key base information; encryptingcontents information into encryption-resultant contents information inresponse to the key signal; and transmitting the encryption-resultantkey base information and the encryption-resultant contents information.4. A method of recording contents information, comprising the steps of:generating a signal representative of a key from authenticator-valueinformation and key base information, the authenticator-valueinformation representing a specified authenticator value, the key baseinformation containing identification information which is set toreproduce the specified authenticator value according to a predetermineddegeneration function; encrypting at least the identificationinformation in the key base information to convert the key baseinformation into encryption-resultant key base information; encryptingcontents information into encryption-resultant contents information inresponse to the key signal; and recording the encryption-resultant keybase information and the encryption-resultant contents information. 5.An apparatus for transmitting contents information, comprising: meansfor generating a signal representative of a key from authenticator-valueinformation and key base information, the authenticator-valueinformation representing a specified authenticator value, the key baseinformation containing identification information which is set toreproduce the specified authenticator value according to a predetermineddegeneration function; means for encrypting at least the identificationinformation in the key base information to convert the key baseinformation into encryption-resultant key base information; means forencrypting contents information into encryption-resultant contentsinformation in response to the key signal; and means for transmittingthe encryption-resultant key base information and theencryption-resultant contents information.
 6. An apparatus for recordingcontents information, comprising: means for generating a signalrepresentative of a key from authenticator-value information and keybase information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;means for encrypting at least the identification information in the keybase information to convert the key base information intoencryption-resultant key base information; means for encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; and means for recording the encryption-resultant keybase information and the encryption-resultant contents information.
 7. Atransmission medium for transmitting encryption-resultant key baseinformation and encryption-resultant contents information, wherein theencryption-resultant key base information and the encryption-resultantcontents information are generated by the steps of generating a signalrepresentative of a key from authenticator-value information and keybase information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal.
 8. A recording medium loaded withencryption-resultant key base information and encryption-resultantcontents information, wherein the encryption-resultant key baseinformation and the encryption-resultant contents information aregenerated by the steps of generating a signal representative of a keyfrom authenticator-value information and key base information, theauthenticator-value information representing a specified authenticatorvalue, the key base information containing identification informationwhich is set to reproduce the specified authenticator value according toa predetermined degeneration function; encrypting at least theidentification information in the key base information to convert thekey base information into encryption-resultant key base information; andencrypting contents information into encryption-resultant contentsinformation in response to the key signal.
 9. A method as recited inclaim 3 , wherein the identification information in the key baseinformation contains at least one of 1) information about a region orregions corresponding to one or more countries, one or more zones, orone or more spaces, 2) information about identification of anindividual, 3) information about identification of a group of persons,4) information about a rating, 5) information about identification of anapparatus maker or a device maker, 6) information about identificationof a contents provider, 7) information about time, 8) information aboutcontents authors, 9) information about identification of a reproducingapparatus or a reproducing device, 10) information about identificationof a connection apparatus or a connection device, 11) information aboutidentification of a medium on which contents information is recorded,12) information about identification of contents information, and 13)information about accounting.
 10. A method of transmitting contentsinformation, comprising the steps of: generating a signal representativeof a key from key base information containing identification informationwhich is set to reproduce a specified authenticator value according to apredetermined degeneration function; encrypting contents informationinto encryption-resultant contents information in response to the keysignal; and transmitting the key base information and theencryption-resultant contents information.
 11. A method of recordingcontents information, comprising the steps of: generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;encrypting contents information into encryption-resultant contentsinformation in response to the key signal; and recording the key baseinformation and the encryption-resultant contents information.
 12. Amethod of transmitting contents information, comprising the steps of:generating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; encrypting at least the identification information in the keybase information to convert the key base information intoencryption-resultant key base information; encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; and transmitting the encryption-resultant key baseinformation and the encryption-resultant contents information.
 13. Amethod of recording contents information, comprising the steps of:generating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; encrypting at least the identification information in the keybase information to convert the key base information intoencryption-resultant key base information; encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; and recording the encryption-resultant key baseinformation and the encryption-resultant contents information.
 14. Anapparatus for transmitting contents information, comprising: means forgenerating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; means for encrypting at least the identification informationin the key base information to convert the key base information intoencryption-resultant key base information; means for encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; and means for transmitting the encryption-resultantkey base information and the encryption-resultant contents information.15. An apparatus for recording contents information, comprising: meansfor generating a signal representative of a key from key baseinformation containing identification information which is set toreproduce a specified authenticator value according to a predetermineddegeneration function; means for encrypting at least the identificationinformation in the key base information to convert the key baseinformation into encryption-resultant key base information; means forencrypting contents information into encryption-resultant contentsinformation in response to the key signal; and means for recording theencryption-resultant key base information and the encryption-resultantcontents information.
 16. A transmission medium for transmittingencryption-resultant key base information and encryption-resultantcontents information, wherein the encryption-resultant key baseinformation and the encryption-resultant contents information aregenerated by the steps of generating a signal representative of a keyfrom key base information containing identification information which isset to reproduce a specified authenticator value according to apredetermined degeneration function; encrypting at least theidentification information in the key base information to convert thekey base information into encryption-resultant key base information; andencrypting contents information into encryption-resultant contentsinformation in response to the key signal.
 17. A recording medium loadedwith encryption-resultant key base information and encryption-resultantcontents information, wherein the encryption-resultant key baseinformation and the encryption-resultant contents information aregenerated by the steps of generating a signal representative of a keyfrom key base information containing identification information which isset to reproduce a specified authenticator value according to apredetermined degeneration function; encrypting at least theidentification information in the key base information to convert thekey base information into encryption-resultant key base information; andencrypting contents information into encryption-resultant contentsinformation in response to the key signal.
 18. A method as recited inclaim 12 , wherein the identification information in the key baseinformation contains at least one of 1) information about a region orregions corresponding to one or more countries, one or more zones, orone or more spaces, 2) information about identification of anindividual, 3) information about identification of a group of persons,4) information about a rating, 5) information about identification of anapparatus maker or a device maker, 6) information about identificationof a contents provider, 7) information about time, 8) information aboutcontents authors, 9) information about identification of a reproducingapparatus or a reproducing device, 10) information about identificationof a connection apparatus or a connection device, 11) information aboutidentification of a medium on which contents information is recorded,12) information about identification of contents information, and 13)information about accounting.
 19. A method of decryptingencryption-resultant contents information generated by an encryptingside which implements the steps of generating a signal representative ofa key from authenticator-value information and key base information, theauthenticator-value information representing a specified authenticatorvalue, the key base information containing identification informationwhich is set to reproduce the specified authenticator value according toa predetermined degeneration function; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; the method comprising the steps of: reproducing theauthenticator-value information representative of the specifiedauthenticator value from the identification information in the key baseinformation according to the predetermined degeneration function;reproducing the key signal from the reproduced authenticator-valueinformation and the key base information; and decrypting theencryption-resultant contents information into the original contentsinformation in response to the reproduced key signal.
 20. A method ofdecrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from authenticator-value information and keybase information, the authenticator-value information representing aspecified authenticator value, the key base information containingidentification information which is set to reproduce the specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; the method comprising the steps of: decrypting theencryption-resultant key base information into the original key baseinformation; reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the original key base informationaccording to the predetermined degeneration function; reproducing thekey signal from the reproduced authenticator-value information and theoriginal key base information; and decrypting the encryption-resultantcontents information into the original contents information in responseto the reproduced key signal.
 21. An apparatus for decryptingencryption-resultant contents information generated by an encryptingside which implements the steps of generating a signal representative ofa key from authenticator-value information and key base information, theauthenticator-value information representing a specified authenticatorvalue, the key base information containing identification informationwhich is set to reproduce the specified authenticator value according toa predetermined degeneration function; encrypting at least theidentification information in the key base information to convert thekey base information into encryption-resultant key base information; andencrypting contents information into encryption-resultant contentsinformation in response to the key signal; the apparatus comprising:means for decrypting the encryption-resultant key base information intothe original key base information; means for reproducing theauthenticator-value information representative of the specifiedauthenticator value from the identification information in the originalkey base information according to the predetermined degenerationfunction; means for reproducing the key signal from the reproducedauthenticator-value information and the original key base information;and means for decrypting the encryption-resultant contents informationinto the original contents information in response to the reproduced keysignal.
 22. A method of decrypting encryption-resultant contentsinformation generated by an encrypting side which implements the stepsof generating a signal representative of a key from key base informationcontaining identification information which is set to reproduce aspecified authenticator value according to a predetermined degenerationfunction; and encrypting contents information into encryption-resultantcontents information in response to the key signal; the methodcomprising the steps of: reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the key base information according to thepredetermined degeneration function; reproducing the key signal from thekey base information; deciding whether or not the reproducedauthenticator-value information is correct; decrypting theencryption-resultant contents information in response to the reproducedkey signal when it is decided that the reproduced authenticator-valueinformation is correct; and altering the reproduced key signal into awrong key signal and decrypting the encryption-resultant contentsinformation in response to the wrong key signal when it is decided thatthe reproduced authenticator-value information is not correct.
 23. Amethod of decrypting encryption-resultant contents information generatedby an encrypting side which implements the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; the method comprising the steps of: decrypting theencryption-resultant key base information into the original key baseinformation; reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the original key base informationaccording to the predetermined degeneration function; reproducing thekey signal from the original key base information; deciding whether ornot the reproduced authenticator-value information is correct;decrypting the encryption-resultant contents information in response tothe reproduced key signal when it is decided that the reproducedauthenticator-value information is correct; and altering the reproducedkey signal into a wrong key signal and decrypting theencryption-resultant contents information in response to the wrong keysignal when it is decided that the reproduced authenticator-valueinformation is not correct.
 24. An apparatus for decryptingencryption-resultant contents information generated by an encryptingside which implements the steps of generating a signal representative ofa key from key base information containing identification informationwhich is set to reproduce a specified authenticator value according to apredetermined degeneration function; encrypting at least theidentification information in the key base information to convert thekey base information into encryption-resultant key base information; andencrypting contents information into encryption-resultant contentsinformation in response to the key signal; the apparatus comprising:means for decrypting the encryption-resultant key base information intothe original key base information; means for reproducing theauthenticator-value information representative of the specifiedauthenticator value from the identification information in the originalkey base information according to the predetermined degenerationfunction; means for reproducing the key signal from the original keybase information; means for deciding whether or not the reproducedauthenticator-value information is correct; means for decrypting theencryption-resultant contents information in response to the reproducedkey signal when it is decided that the reproduced authenticator-valueinformation is correct; and means for altering the reproduced key signalinto a wrong key signal and decrypting the encryption-resultant contentsinformation in response to the wrong key signal when it is decided thatthe reproduced authenticator-value information is not correct.
 25. Amethod of decrypting encryption-resultant contents information generatedby an encrypting side which implements the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;and encrypting contents information into encryption-resultant contentsinformation in response to the key signal; the method comprising thesteps of: reproducing the authenticator-value information representativeof the specified authenticator value from the identification informationin the key base information according to the predetermined degenerationfunction; reproducing the key signal from the key base information;deciding whether or not the reproduced authenticator-value informationis correct; decrypting the encryption-resultant contents information inresponse to the reproduced key signal when it is decided that thereproduced authenticator-value information is correct; and failing todecrypt the encryption-resultant contents information in response to thereproduced key signal when it is decided that the reproducedauthenticator-value information is not correct.
 26. A method ofdecrypting encryption-resultant contents information generated by anencrypting side which implements the steps of generating a signalrepresentative of a key from key base information containingidentification information which is set to reproduce a specifiedauthenticator value according to a predetermined degeneration function;encrypting at least the identification information in the key baseinformation to convert the key base information intoencryption-resultant key base information; and encrypting contentsinformation into encryption-resultant contents information in responseto the key signal; the method comprising the steps of: decrypting theencryption-resultant key base information into the original key baseinformation; reproducing the authenticator-value informationrepresentative of the specified authenticator value from theidentification information in the original key base informationaccording to the predetermined degeneration function; reproducing thekey signal from the original key base information; deciding whether ornot the reproduced authenticator-value information is correct;decrypting the encryption-resultant contents information in response tothe reproduced key signal when it is decided that the reproducedauthenticator-value information is correct; and failing to decrypt theencryption-resultant contents information in response to the reproducedkey signal when it is decided that the reproduced authenticator-valueinformation is not correct.
 27. An apparatus for decryptingencryption-resultant contents information generated by an encryptingside which implements the steps of generating a signal representative ofa key from key base information containing identification informationwhich is set to reproduce a specified authenticator value according to apredetermined degeneration function; encrypting at least theidentification information in the key base information to convert thekey base information into encryption-resultant key base information; andencrypting contents information into encryption-resultant contentsinformation in response to the key signal; the apparatus comprising:means for decrypting the encryption-resultant key base information intothe original key base information; means for reproducing theauthenticator-value information representative of the specifiedauthenticator value from the identification information in the originalkey base information according to the predetermined degenerationfunction; means for reproducing the key signal from the original keybase information; means for deciding whether or not the reproducedauthenticator-value information is correct; means for decrypting theencryption-resultant contents information in response to the reproducedkey signal when it is decided that the reproduced authenticator-valueinformation is correct; and means for failing to decrypt theencryption-resultant contents information in response to the reproducedkey signal when it is decided that the reproduced authenticator-valueinformation is not correct.
 28. A method as recited in claim 19 ,wherein the identification information in the key base informationcontains at least one of 1) information about a region or regionscorresponding to one or more countries, one or more zones, or one ormore spaces, 2) information about identification of an individual, 3)information about identification of a group of persons, 4) informationabout a rating, 5) information about identification of an apparatusmaker or a device maker, 6) information about identification of acontents provider, 7) information about time, 8) information aboutcontents authors, 9) information about identification of a reproducingapparatus or a reproducing device, 10) information about identificationof a connection apparatus or a connection device, 11) information aboutidentification of a medium on which contents information is recorded,12) information about identification of contents information, and 13)information about accounting.